rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (0 ticks this GP) idle=2d8c/1/0x4000000000000000 softirq=14464/14464 fqs=2
rcu: (detected by 1, t=10502 jiffies, g=14817, q=635 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 2994 Comm: kworker/u4:13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0x1024/0x7d40 kernel/locking/lockdep.c:5132
Code: 44 89 f3 c1 c3 13 44 29 f1 31 cb 41 01 d6 29 da 41 89 dc 41 c1 c4 04 41 31 d4 48 c7 c0 a0 6f 8b 8e 48 c1 e8 03 42 0f b6 04 00 <84> c0 0f 85 f6 5c 00 00 41 01 de 83 3d 2a 2a 23 0d 00 4c 8b 7c 24
RSP: 0018:ffffc900000078a0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: 00000000d9f4e301 RCX: 0000000051899f90
RDX: 00000000de7ba55a RSI: 000000002fc63f8d RDI: ffffffff911c9500
RBP: ffffc90000007ae8 R08: dffffc0000000000 R09: 1ffffffff22392a0
R10: dffffc0000000000 R11: fffffbfff22392a1 R12: 0000000041359547
R13: ffff88802bf01e00 R14: 000000006802b96a R15: 00000000b8839213
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa5f0798d58 CR3: 0000000028d90000 CR4: 00000000003506f0
Call Trace:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
debug_object_deactivate+0x67/0x390 lib/debugobjects.c:764
debug_hrtimer_deactivate kernel/time/hrtimer.c:455 [inline]
__run_hrtimer kernel/time/hrtimer.c:1722 [inline]
__hrtimer_run_queues+0x2cb/0xc40 kernel/time/hrtimer.c:1818
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1880
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline]
RIP: 0010:__local_bh_enable_ip+0x142/0x1c0 kernel/softirq.c:413
Code: 8a e8 12 f6 34 09 65 66 8b 05 4a 4a b1 7e 66 85 c0 75 54 bf 01 00 00 00 e8 8b 22 0a 00 e8 b6 32 3b 00 fb 65 8b 05 16 4a b1 7e <85> c0 75 05 e8 95 31 ae ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc9000c667a20 EFLAGS: 00000282
RAX: 0000000080000000 RBX: 0000000000000201 RCX: 79c9f3dc0017e600
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1c9a20
RBP: ffffc9000c667ab8 R08: ffffffff911c95df R09: 1ffffffff22392bb
R10: dffffc0000000000 R11: fffffbfff22392bc R12: ffffffff8a4f05c1
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffff920018ccf44
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x311/0x3a0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x369/0x610 net/batman-adv/network-coding.c:722
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: rcu_preempt kthread starved for 10490 jiffies! g14817 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:27656 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 6282 Comm: syz.1.129 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfe/0x1140 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 4b f7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 86 f3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 6a f3
RSP: 0018:ffffc9000bebf4c0 EFLAGS: 00000293
RAX: ffffffff817c3886 RBX: 1ffff110171c8759 RCX: ffff888024ac8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000bebf640 R08: ffffc9000bebf447 R09: 1ffff920017d7e88
R10: dffffc0000000000 R11: fffff520017d7e89 R12: ffff8880b8e43ac8
R13: dffffc0000000000 R14: ffff8880b8f3d148 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe796ffff6c CR3: 0000000061e28000 CR4: 00000000003506e0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
__flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:990 [inline]
flush_tlb_mm_range+0x424/0x6a0 arch/x86/mm/tlb.c:1078
tlb_flush arch/x86/include/asm/tlb.h:20 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:474 [inline]
tlb_flush_mmu+0x1bd/0x510 mm/mmu_gather.c:300
tlb_finish_mmu+0xf9/0x220 mm/mmu_gather.c:425
exit_mmap+0x428/0xb90 mm/mmap.c:3315
__mmput+0x118/0x3c0 kernel/fork.c:1357
exit_mm+0x24a/0x350 kernel/exit.c:570
do_exit+0x8dd/0x2460 kernel/exit.c:871
do_group_exit+0x21b/0x2d0 kernel/exit.c:1026
get_signal+0x12fc/0x13f0 kernel/signal.c:2902
arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb77ff9ce59
Code: Unable to access opcode bytes at 0x7fb77ff9ce2f.
RSP: 002b:00007fb77e1d50e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fb780216098 RCX: 00007fb77ff9ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb780216098
RBP: 00007fb780216090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb780216128 R14: 00007fffde065930 R15: 00007fffde065a18